1. 9/3/2004 ALCPG Calorimetry Status J. Yu 1 Summary of North American Calorimeter R&D Efforts *On behalf of all N.A. Calorimeter Groups Introduction – Some calorimeter R&D Issues Particle Flow Algorithm Development ECAL –Si/W –Scintillator/W HCAL –Scintillator/Steel –RPC/Steel Summary Sept. 3, 2004 ECFA Workshop, Durham Jae Yu* University of Texas at Arlington

2. 9/3/2004 ALCPG Calorimetry Status J. Yu 2 Some Calorimeter R&D Issues Simulations  Evaluate EFlow 1.Full simulation [ Gismo→Geant4 ] 2.Pattern recognition algorithms [ emerging…], merge with tracks, etc → Full reconstruction [ JAS, Root ] 3.Optimize detector configuration  Case for jet physics Low-rate processes ( eg Zhh, tth) Beam constraints vs not reduce combinations for mult-jet recon. (eg tt→6 jets) How to combine with other info. ( eg flavors from vxd)  e, photon id; muon id; forward (2-photon), missing E  Timing requirement (viz. 2-photon, beam bkgds.) Opportunities: algorithm development, validity of Geant4, parameterizations, detector ideas

3. 9/3/2004 ALCPG Calorimetry Status J. Yu 3  Si/W Cost, readout config., packaging, cooling Mechanical structure Optimize sampling vs Si area  Alternatives! [issues] Scint. tiles [segmentation, light output, readout] With Si layer(s) ? Shashlik [segmentation] Crystals [segmentation, physics case for reso.? ] LAr Opportunities: generic detector development; detector and electronics prototyping; comparative and detailed simulations EM Calorimeter R&D Issues

4. 9/3/2004 ALCPG Calorimetry Status J. Yu 4  Required segmentation for EFlow?  “Digital’’ detector [issues] RPCs [reliability, glass?, streamer/avalanche] Scint. [segmentation, light, readout] GEMs [scalability, long term reliability]  Other options Scint. tiles, ….?  Generic Issues: In/out –side coil Compensation (partial?) Absorber material and depth Integrate muon id with dedicated muon det. Opportunities: Wide open: detailed simulations in conjunction with various detector options; detector prototyping HAD Calorimeter R&D Issues

5. 9/3/2004 ALCPG Calorimetry Status J. Yu 5 Sept. 2004: Where are we? Essentially all issues are being/have been addressed… …at “some level”  not necessarily a good level Development of full particle flow algorithm codes –Goal: Physics signals (jet final states) optimized as a function of basic detector parameters: B, R trk, cal. segmentation, etc. –Parts of problem have been attacked incompletely –Not easy! Needs to be recognized as a top R&D priority. Validation of key, new detector innovations Validation of the MC codes for simulating hadronic showers which in turn will be used to design the calorimeter (using PFAs). This is fundamental to calorimeter progress.  Prototypes in a test beam  Funding a serious issue to be timely

6. 9/3/2004 ALCPG Calorimetry Status J. Yu 6 Hadronic final states and PFAs LHC Study: Z→ 2 jets D. Green, Calor2002 FSR is the biggest effect. The underlying event is the second largest error (if cone R ~ 0.7). Calorimeter resolution is a minor effect. σ M / M  13% without FSR  At the LC, the situation is reversed: Detection dominates.  Opportunity at the LC to significantly improve measurement of jets.

7. 9/3/2004 ALCPG Calorimetry Status J. Yu 7 Particle flow and calorimeters (cont’d) Complementarity with LHC: LC should strive to do physics with all final states. 1.Charged particles in jets more precisely measured in tracker 2.Jet energy 64% charged (typ.) Separate charged/neutrals in calor.  The “Particle Flow” paradigm ECAL: dense, highly segmented HCAL: good pattern recognition H. Videau

8. 9/3/2004 ALCPG Calorimetry Status J. Yu 8 Particle-Flow Implications for Calorimetry Traditional Standards Hermeticity Uniformity Compensation Single Particle E measurement Outside “thin” magnet (~1 T) P-Flow Modification H ermeticity Optimize ECAL/HCAL separately Longitudinal Segmentation Particle shower reconstruction Inside “thick” coil (~4 T) Optimized for best single particle E resolution Optimized for best particle shower separation/reconstruction 3-D shower reconstruction in ECAL/HCAL requires high degree of longitudinal segmentation and transverse granularity S. Magill

9. 9/3/2004 ALCPG Calorimetry Status J. Yu 9 calorimetry (cont’d) So the “confusion” term – correctly assigning energies – will dominate  pattern recognition (+ QCD). 0.3/  Ejet is a reasonable goal with good physics justification. Reconstructing jets using particle flow algorithms: Inserting resolutions for charged hadrons (tracker)  64% E jet photons (EM cal.)  25% E jet neutral hadrons (hadronic cal.)  11% E jet D. Karlen

10. 9/3/2004 ALCPG Calorimetry Status J. Yu 10 Shower reconstruction by track extrapolation Mip reconstruction : Extrapolate track through CAL layer-by-layer Search for “Interaction Layer” -> Clean region for photons (ECAL) Shower reconstruction : Define tubes for shower in ECAL, HCAL after IL Optimize, iterating tubes in E,HCAL separately (E/p test) ECAL HCAL track IL shower S. Magill

11. 9/3/2004 ALCPG Calorimetry Status J. Yu 11 Jet cones – 0.5 Neutral contribution to E sum ~3.7 GeV (most) -> Goal is ~3 GeV (all) Track Substitution, Neutral Sum Results G4v6.1 Includes mips + cell energies in conical tubes Further tuning of E/p parameter is still needed Charged Neutral

12. 9/3/2004 ALCPG Calorimetry Status J. Yu 12 It’s not just for jet physics… Such a calorimeter will also do very well for: –Photons, including non- pointing –Electrons and muons Tau id. and polarization –3rd generation –Yukawa coupling –Separation of tau final states  →  →  +  o Brient, Calor2004  → , 

13. 9/3/2004 ALCPG Calorimetry Status J. Yu 13 Possible LC Calorimeter Themes Current paradigms ECal: Silicon/tungsten HCal: –“ Analog” (5-10 cm seg.) CALICE tile-cal (TESLA) –“Digital” (1 cm seg.) SiD: RPCs, GEMs CALICE: RPCs, GEMs Alternatives ECal: –Si/scint/W hybrids –Scint/W –Scint/Pb HCal: –Scint/Pb → Large/Huge Detectors

14. 9/3/2004 ALCPG Calorimetry Status J. Yu 14 What’s New: Silicon/W, SLAC-Oregon-BNL

15. 9/3/2004 ALCPG Calorimetry Status J. Yu 15 what’s new Si/W (SOB), cont’d Dynamically switched C f –Much reduced power –Much better S/N –Allows for good timing measurement

16. 9/3/2004 ALCPG Calorimetry Status J. Yu 16 Timing with Si/W ECal 50 ns time constant and 30-sample average  ns resolution Concerns & Issues: Needs testing with real electronics and detectors verification in test beam synchronization of clocks (1 part in 20) physics crosstalk For now, assume pileup window is ~5 ns (3 bx) D. Strom Concern reduced now!

17. 9/3/2004 ALCPG Calorimetry Status J. Yu 17 What’s New: Scintillator/W ECal, Colorado (cont’d) U. Nauenberg

18. 9/3/2004 ALCPG Calorimetry Status J. Yu 18 Needs validation in test beam Digital HCal with Scintillator (NIU) Density based PFA recon inside jets

19. 9/3/2004 ALCPG Calorimetry Status J. Yu 19 Stack & Tile Fabrication ~15pe/mip

20. 9/3/2004 ALCPG Calorimetry Status J. Yu 20 Tile-Fiber-Reflector Optimization No ageing

21. 9/3/2004 ALCPG Calorimetry Status J. Yu 21 Relative LY cast extruded

22. 9/3/2004 ALCPG Calorimetry Status J. Yu 22 Reflector Performance

23. 9/3/2004 ALCPG Calorimetry Status J. Yu 23 Scintillator/Steel HCAL Status Simulations and prototyping studies indicate approach competitive with other options. Detailed R&D studies on tile-fiber-reflector optimization, photo-detector characterization, efficient assembly have been successfully completed. Focus shifting to test beam prototype

24. 9/3/2004 ALCPG Calorimetry Status J. Yu 24 AIR4 is a 1-gap RPC built with 1.1mm glass sheet –1.2mm gap size –Resistive paint layer is about 1MΩ/ □ Running at 6.8 KV –Avalanche signal ~5pc –Efficiency >97% Total RPC rate from 64 channels <10 Hz –Very low noise! Pad array Mylar sheet Aluminum foil 1.1mm Glass sheet Resistive paint (On-board amplifiers) 1.2mm gas gap -HV GND What’s New: DHCal with RPCs, ANL

25. 9/3/2004 ALCPG Calorimetry Status J. Yu 25 ANL RPC R&D Plan R&D with chambers –Essentially completed Electronic readout system –Design and prototype ASIC –Specify entire readout system –Prototype subcomponents Construction of m3 m3 Prototype Section –Build chambers –Fabricate electronics Tests in particle beam –Without and with ECAL in front

26. 9/3/2004 ALCPG Calorimetry Status J. Yu 26 Calorimeter R&D Summary CalorimeterTechnologyGroups Electromagnetic Silicon-TungstenBNL, Oregon, SLAC Silicon-TungstenBritain, Czech, France, Korea, Russia Scintillator/Silicon-LeadItaly Scintillator/Silicon-TungstenKansas, Kansas State Scintillator-LeadJapan Scintillator-TungstenColorado Hadronic (analog) Scintillator-SteelCzech, Germany, Russia NIU Scintillator-LeadJapan Hadronic (digital) Gas Electron Multipliers-SteelFNAL, UT Arlington Resistive Plate Chambers-SteelRussia Scintillator – SteelNothern Illinois/ NICADD Resistive Plate Chamber-SteelANL, Boston, Chicago, FNAL Tail catcher Scintillator-SteelFNAL, Northern Illinois Resistive Plate Chambers-SteelItaly

27. 9/3/2004 ALCPG Calorimetry Status J. Yu 27 Comparison of hadron shower simulation codes by G Mavromanolakis Validate various technical approaches (technique and physics) Many novel concepts: Fine granularity E/HCAL, DHCAL, Calorimeters with RPCs/GEMs, SiPMs… Validate various concepts of the electronic readout Many novel concepts: Imbedded ECAL readout, cheap digital readout… Measure hadronic showers with unprecedented spatial resolution Validate MC simulation of hadronic showers Compare performance of Analog and Digital HCAL Prerequisite for designing the LCDs J. Repond

28. 9/3/2004 ALCPG Calorimetry Status J. Yu 28 Particle Flow will be tested and detectors optimized using full Monte Carlo simulations These Monte Carlos (ie Geant4) must be validated with test beam –A new regime: “Imaging” hadron (and em) calorimeters –Previous MC-cal comparisons not especially relevant Hadron showers are spatially large  a large prototype is needed (with an ECal in front) –1 m 3,  4  10 5 readout channels This requires funds (more than current LCRD/UCLC awards) Meanwhile, initial R&D goals are at or near completion The Test Beam Prototypes

29. 9/3/2004 ALCPG Calorimetry Status J. Yu 29 Significant progress made in N.A. Calorimeter R&D Based on preliminary Particle Flow results and educated guesses, the critical detector R&D has gone very well. We have learned much about LC requirements –eg timing and hermeticity requirements (The ITRP process) Further progress on PFAs is critical for detector optimization Test beam validation of simulations is crucial for the cal. effort. –This can go on in parallel with the PFA developments Strong funding support is needed for the quantum jump to the next step Plan to participate in the world-wide effort for a coherent Test Beam program Summary